Ethaw i



E. I, DODDS.

STAY BOLT FOR BOILERS.

APPLICATIQN man NOV. 30, 1914.

1 (,1 9%,24. Patented Aug. 15, 1916.

l V/T VESSES //VVENI OA Aflormy E TED 1 T ETHAN I. DODDS, OF PITTSBURGH,PENNSYLVANIA, ASSIGNOR TO FLANNERY BOLT COMPANY, OF PITTSBURGH,PENNSYLVANIA.

STAY-BOLT FOR BOILERS.

Application filed November 30, 1914.

To aZZ whom it may concern:

Be it known that I, ETHAN I. Donne, a citizen of the United States, anda resident of Pittsburgh, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inStay-Bolts for Boilers; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to an improvement in stay bolts for boilers, theobject being to provide a bolt the shank of which will be yielding orflexible so that it may accommodate itself to the unequal movement ofthe two sheets to which it is secured, without impairing its efficiencyto withstand longitudinal stresses to which it may be subjected whenapplying it to the sheets, or when the boiler is in use.

\Vith this object in view my invention consists in the details ofconstruction as will be more fully explained and pointed out in theclaims.

In the accompanying drawings, Figure 1 is a View in elevation of a staybolt blank embodying my invention; Figs. 2 and 3 are views in transversesection on the lines 22 and 33 respectively of Fig. 1; Fig. 4: is a viewpartly in elevation and partly in longitudinal section of a modifiedform of bolt, and Figs. 5 and 6 are views in transverse section 011lines 55 and 66 respectively of the bolt shown in Fig. 4f.

In the manufacture of the bolt, a bar of stay bolt metal preferablycylindrical is subjected to an upsetting heat and swaged between dies orother suitable tools to produce the reduced shank 1 and the enlargedheads 2 and 3. During the operation of swaging or before or after thesame, the shank 1 of the bolt is slotted on its opposite sides part waythrough. This slotting as at 4, is continuous throughout the length ofthe shank, and is deepest from the head 2 to about midway the shank, orto the point 7 5, the web 6 separating the two slots at this end of theshank being comparatively thin. From the point 5 to the other head 3,the slots are much shallower, so that the web 7 separating them isthicker, thus making the half of the shank adjacent the head 3, flexibleto a certain extent but more rigid than the half adjacent the head 2,thus localizing Specification of Letters Patent.

Patented Aug. 15, 1916.

Serial no. 874,825.

' contraction and expansion of the inner and outer sheets of the boiler,to that portion of the shank which is adjacent the outer head of thebolt. This outer head of the bolt is provided with a tell tale hole 7for the escape of steam or water in the event the bolt should break. Thegreatest stresses fall on a stay bolt adjacent the outer head, hence bymaking this part of the bolt so that it will yield or give with theboiler sheets instead of resisting their movements, the danger ofbreakage is reduced'to a minimum, but if it should break, the fracturewill expose the tell-tale bore and permit the steam to es cape.Substantially the same result-may be accomplished with the constructionshown in Figs. at to G inclusive. In this latter form, each slot extendsall the way through for about half the length of the shank and part waythrough for the remainder of the way. Thus the sloti starting from head.2 passes entirely through the shank to the point 9, leaving the web 10separating the ends thereof adjacent the bolt head -3,while the slot 1-,which is at right angles to slot 45, starting from head 8, extendsthrough the web 10 and after it leaves the end 9 of the latter, itdivides and is separated by a web 10 With this construction the shank ofthe bolt is flexible throughout its length, but as the side walls of theslots are tied by the webs 10 and 10, there can be no buckling orbinding of the shank, dueto endwise stress either pulling orcompressive. This slotting does not remove any of the metal but simplypierces it so that the capacity of the shank for endwise stresses is notweakened, and renders the shank sufficiently flexible laterally so as topermit it to give or yield and thus accommodate itself to the unequalexpansion of the inner and outer sheets of the boiler.

Having fully described my invention what I claim as new and desire tosecure by Letters-Patent, is

1. As a new article of manufacture, a stay bolt the shank of which isprovided with .slots each extending lengthwise the shank, and anintegral web separating said slots and reducing the depth of thelatteradjacent one head.

2. As a new article of manufacture, a stay bolt having integral headsand a shank Copies of this patent may be obtained for length, the saidslots being separated by an integral web.

In testnnony whereof I have signed this specification 1n the presence oftwo subscribmg witnesses.

ETHAN I. DODDS.

\Vitnesses l VM. CHARLES BINGHAM, EDWIN SPENCER RYOE.

five cents each, by addressing the Commissioner of ?a.tents, Washington,D. C.

